These were my specific questions:
Does "generosity" mean that the individuals feel or are generous themselves (which feels good)?
Does it mean that the individuals experience generosity by their fellow citizens (which would affect happiness in a different way)?
Does it mean that the individuals experience generosity by their government or employer or other superior party?
Does it mean all of this together, giving a cumulated number of some kind?
Why is generosity preferred to other similar factors like fairness or solidarity?
At Politics (Beta) I got this answer:
Generosity is the residual of regressing the national average of GWP responses to the question “Have you donated money to a charity in the past month?” on GDP per capita.
But for several reasons, this question - even with regression to GDP per capita - doesn't give a good measure for generosity, I believe:
Many people (in the Western world) donate money mainly around Christmas.
The amount of money they donate can hardly be considered really "generous".
Many people in poorer regions of the world don't have enough money to give some of it away (but possibly other things).
So my questions are:
Why did "generosity" enter into the World Happiness Score nevertheless, and in the way it does? And why so prominently, on an equal footing with social support, healthy life expectancy, freedom to make life choices, and - also quite surprisingly - perceptions of corruption?
Why is especially "generosity" believed to help quantifying "happiness"?
(Of course it's easy to believe that someone who is generous and experiences generosity is happier than someone who is greedy and experiences greed. But the same holds for fairness, solidarity, etc.)